Damper assembly



Dec. 23, 1969 EQKAHN ET AL DAMP ER A S S EMBLY 2 Sheetsl-Sheet 1 Filed June 17, 1968 FIG.1

INVENTORS EN of Kahn Aex Babi-'wich maw..-

'llllIHl ATTORNEY Dec. 23, 1969 E, KAHN ET AL DAMPER ASSEMBLY 2 Sheets-Sheet 2 FIG. 5

Filed June 17, 1968 FIGA 3,484,990 DAMPER ASSEMBLY Elliot Kahn, New Rochelle, and Alex Bobrowich, Bronx,

N.Y., assignors to Arrow Louver and Damper Corporation, Maspeth, N Y.

Filed June 17, 1968, Ser. No. 737,412 Int. Cl. E06b 7/08 U.S. Cl. 49-91 1 Claim ABSTRACT oF THE DIscLosURE BACKGROUND OF THE INVENTION Field of the invention This invention relates to air or gas flow controlling means such as an adjustable damper blade asembly, and more particularly, to a plurality of damper blade members which overlap in their closed position, and which are provided with sealing means on their longitudinal edge portions for making sealing contact with opposed portions of adjacent blade members in the closed position thereof.

Description of the prior art The present invention is an improvement over applicants earlier Patent No. 3,084,405 for a Damper Assembly, isued Apr. 9, 1963. The damper blade of the aforesaid patent comprises a solid cross-section member having a substantially flat longitudinally extending central portion and a pair of longitudinal edge portions that extend angularly, at an angle of less than 90, with respect to said central portion, and in opposite directions therefrom. The construction is such that in the closed position of the damper blades, the edge portions of adjacent blades overlap and interlock to provide a seal against air and gas flow through the damper assembly.

Heretofore, various arrangements have been proposed to provide a more effective sealing construction, usually having a flexible sealing means mounted on the blade edges which are inter-engageable with similar means on an adjacent blade or directly engageable with an edge of the adjacent blade. Such arrangements have not proven entirely satisfactory for the main reason that the sealing means did not provide sucient sealing contact with the opposed surface portion of the adjacent overlapping blade.

Further diflculties have been encountered in the damper asembly of the aforesaid patent with respect to the manner in which the blades are mounted on their respective operating shafts. For example, each blade is formed at the center line of its midsection with an arcuately offset circular portion having ribs extending from the inner surface thereof; said ribs extending at an angle to each other and constituting radii of said circularly offset arcuate portion. These ribs are arranged to slidably interfit with corresponding grooves or slots formed in a generally cylindrical operating shaft, whereby each blade is assembled to its operating shaft by sliding the same longitudinally thereof with the ribs on the blade engaging in the grooves or slots in the operating shaft. It has been found, however, that Patent O the blades may crack or rupture at the point where the arcuately offset circular portion is formed due to the forces that are imposed on said blades when they are moved between open and closed positions.

The present invention eliminates the above problems and disadvantages in a manner hereinafter described.

SUMMARY OF THE INVENTION The damper assembly of the present invention provides for blade member to have a central portion and offset longitudinal edge portions extending from opposite sides thereof. Sealing means are mounted on said edge portions and project, respectively, in opposite directions for making extended flat sealing contact with opposed surface portions of adjacent overlapping blade members in the closed position thereof. Additional sealing means are mounted on the side frame members of the supporting assembly structure which engage the ends of the blades in the closed position thereof to form an airtight seal. The central portion of each blade is provided with a partial hub portion which serves to mount said blade to its operating shaft; said partial hub portion extending over an angle greater than to provide reinforcement at the juncture of said central and hub portions.

Accordingly, an object of the prese-nt invention is to provide a damper blade having a novel cross-sectional area whereby it may readily overlap with adjacent blades in the closed position of the damper assembly to prevent air or gas liow therethrough.

Another object of the present invention is to provide a damper blade having sealing means on the longitudinal edge portions thereof for making extended flat sealing contact with an opposed surface portion of the adjacent overlapping blades in the closed position of the damper assembly.

A further object of the present invention is to provide an improved damper blade having sufficient strength and rigidity to withstand the high static pressures of given fluid flow systems.

Another object and feature of the present invention is to provide an improved damper blade which is relatively simple in construction, inexpensive to fabricate and gives long-lasting service.

A further feature of the invention resides in the provision that the damper blade can be readily extruded as an integrally formed part and can be readily cut to any desired length necessary for any given application.

The above and other features and advantages of the present invention will become more apparent from the consideration of the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a front elevational view of a damper assembly embodying the damper blades constructed in accordance with the present invention;

FIG, 2 is an end elevational view of the assembly of a blade and its operating shaft;

FIG. 3 isl a sectional view takenthrough line 3-3 of FIG. l;

FIG. 4 is an end elevational view of the damper assembly of FIG. 1, with parts broken away and parts in section, showing the ,linkage assembly for interconnecting and operating adjacent blades in opposing directions, the phantom lines showing the blades in their closed position;

FIG. 5 is a view -similar to FIG. 4 showing another embodiment of the linkage assembly for interconnecting and operating the blades in the same direction; and

FIG. 6 is an enlarged sectional view taken through line 6-6 of FIG. 1.

3 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, particularly FIGURE l, numeral represents a damper blade assembly including a plurality of damper blades 30 mounted in a substantially rectangular frame 12 including top member 14, side members 16 and 18, and bottom member 20. The blades 30 are oscillatable about the axis of blade shafts 40, described more fully hereinafter, which are rotatably supported in suitable bushings set in uniformly spaced apertures in side frame members 16 and 18. If desired, the frame members may be braced by suitable gussets (not shown) at each corner of the frame. Each shaft may have a link or crank 22 secured thereto (FIG. 4) whereby the blades may be interconnected by a suitable operating rod 24. One of the blades may be operated by a crank or the like, which has not been illustrated, whereby all the blades may be interconnected by a suitable operating rod that the operating crank may be connected for either manual or power operation. Furthermore, as shown in FIGS. 4 and 5, the linkage assembly for interconnecting the blades 30 can be suitably arranged for operating and moving adjacent blades in either the same or opposing directions. In the arrangement shown in the drawings, the operating mechanism for the damper blades is adapted to be concealed and partially enclosed within one of the side members of the frame so as not to obstruct the uid -ow system in which such damper blades are used. The frame members are all cut from suitable angle or channel frame sections, preferably formed of extruded aluminum or other suitable lightweight, high strength material.

Similarly, the damper blades 30 comprise a predetermined length of extruded aluminum material which can be readily cut to size from an elongated length of extruded stock material. It is contemplated that by stocking extruded lengths of damper blades having constructions of varying widths, that any size damper blade can be readily formed simply by cutting from such stock material the length required from the prescribed width stock.

If desired, instead of there being a shaft 40 extending completely across the frame at each blade position, the shaft 40 may be divided into a pair of short stub shafts extending from the ends of each damper blade for mount ing same within the side frame members. In this case, each end stub shaft is assembled to the blade before the latter is mounted within the frame, or the stub shafts and blade may be assembled by positioning the blade between the side frame members and then pushing the stub shafts inwardly to engage into the blade in a manner described more fully hereinafter.

Referring to FIGURE 2, the blade includes a central portion 32 and oiset edge portions 34. Central portion 32 is preferably at and substantially uniplanar except for a partial hub portion 36 extending longitudinally up said blade member and projecting on opposite sides thereof. In the preferred embodiment, the partial hub portion 36 extends along the longitudinal center line of central portion 32 and is centered at an axis midway between the opposite surfaces of said central portion. The hub portion 36 is provided with a plurality of ribs 38 extending inwardly therefrom at substantially right angles to each other and displaced angularly 90 from each other. Accordingly, the prolongation of the ribs 38 will intersect at a center point or axis which is midway between the opposite surfaces of the planar portions of central portion 32. As illustrated in FIGURE '2, partial hub portion 36 extends over an angle greater than 180 to provide reinforcement at the juncture of said central portion 32 and hub portion 36 to thereby eliminate one of the problems heretofore mentioned with respect to known damper blade constructions.

The central portion 32 of each blade member 30 is illustrated as lying in a first plane, whereas the edge portions 34 are provided with respective surfaces 44 lying in a 4 plane substantially parallel to said first plane. The offset edge portions 34 are joined to the marginal ends of the central portion 32 by means of intermediary portions 46. Intermediary portions 46 extend angularly with respect to the general plane of central portion 32 and further extend in opposite directions from said central portion at the respective marginal edges thereof. Preferably, intermediary portions 46 extend at an angle of 45 to the general plane of central portion 32. Accordingly, the respective surfaces 44 of edge portions 34 are offset from the central portion 32 of blade member 30 and extend respectively from opposite sides thereof.

In accordance with the present invention, sealing means 50 are mounted on said edge portions 34 and project respectively in opposite directions for making sealing contact with opposed portions of adjacent blade members in the closed position thereof. Referring to FIGURES 2, 4 and 6, the opposed preferably flat surfaces 44 of edge portions 34 are provided with respective dove tail slots or grooves 52 extending longitudinally the length thereof. sealing means 50 make extended flat sealing contact with complementary dove tail head portions 54 which are fitted into the slots 52. Sealing means 50 may be formed of any suitable, flexible strip of material such as natural or synthetic rubber, plastic and the like. In the preferred embodiment, sealing means 50 are constructed having respective annular cross-sectional surface portions 56. The construction is such that surface lportions 56 of sealing means 50 make extended ilat sealing contact with opposed surface portions of adjacent overlapping blade members when the damper assembly is in the closed position.

Blades 30 are yconnected to shafts 40 by relatively longitudinal sliding movement to form the assembly illustrate in FIGURE 2. As stated, there may be either a single shaft extending the full length of the blade or there may be two stub shafts extending from the ends of the blade for mounting same within the side frame members. Shaft 40 is an extruded or otherwise formed aluminum or aluminum alloy cylindrical rod having formed therein four longitudinally extending slots 42 with an angular spacing of 90 from each other. Slots 42 are provided with rounded inner ends and preferably rounded outer corner edges. It will be noted that when ribs 38 are engaged in slots 42, the blade 30 is locked or keyed to the shaft 40 and can be removed therefrom only by relative longitudinal sliding movement.

In FIGURE 37 there is illustrated a cross-section view of one of the side members of the rectangular frame 12. Side member 18 is formed from a cut to length piece of a channel section preferably extruded of aluminum or aluminum alloy; said channel section having base portion 60 and flanges 62. The inner surface of the channel base 60 is thickened in a zone centrally of the base and the outer surface of said base is formed with a pair of dovetail slots 64 extending longitudinally thereof opposite said thickened Zone and equidistant on either side of the base center line. Sealing means 66 are provided having complementary dove-tail head portions which are slidably received in slots 64; said sealing means being formed of the same material used to form sealing means 50. In the preferred embodiment, sealing means 66 is provided with a plurality of flexible ngers 68 which engage the ends of blades 30 when the assembly is closed, thus forming an airtight seal. The opposing side frame member 16 is similarly constructed for receiving conforming sealing means which engage the opposite ends of blades 30 when the assembly is in the closed position.

Referring to FIGURES 4 and 5a the top and bottom members 14 and 20 of frame 12 are provided with`L- section angle brackets 70 which act as stop means for the rotatable'blades. Accordingly, when blades 30 are in their closed position, sealing means 50 mounted on the upper and lower blades engage legs 72 of said angle brackets 70 to form an airtight seal between said blades and the top and bottom frame members.

In the open position of the blades, the edge portions 34 act as diverters so that there is no direct draft through the damper assembly, the edge portions 34 acting to deect the flow of air or gas therethrough in an upward or downward direction relative to the damper assembly.

From the foregoing description, it will be readily apparent that the damper blade described above is constructed having a strength and rigidity capable of resisting the high static pressure in a given fluid-How system in which such damper blades are used. Furthermore, the present invention overcomes the sealing problems heretofore existing in damper blade assembly constructions.

We claim:

1. In combination with a damper blade assembly comprsing a plurality of blade members movable between wpen and closed positions, the longitudinal marginal por rions of adjacent blade members being in overlapping relation in the closed position thereof; each blade member having a tiat central portion lying in a rst plane, shaft means extending longitudinally of said central portion to deline the axis about which said blade member pivots and means for connecting said central portion to said shaft, wherein the improvement comprises:

(a) the edge portions of each blade member being References Cited UNITED STATES PATENTS 9/1932 4/1933 2/1936 l/l960 7/1962 4/1963 12/1963 3/1964 l2/l966 Burgess 49-89 X Truax 49-82 Strawsine 49--92 X Urban 49-92 Hinden 49-92 X Kahn et al 49--91 X Shustrom 160--236 X Wiley 4977 Okumoto 160-236 X DAVID I. WILLIAMOWSKY, Primary Examiner P. C. KANNAN, Assistant Examiner U.S. Cl. XR. 

